1 went
2 have been
3 came, had, read, began
4 When did your friend return...?-returned - Did you go...?-No, I was too busy.
5 did you discuss...?
6 have seen
7 entered, saw, standing...and cutting. She was cooking...
8 heard, ran, saw, was lying... and crying. What happened (has happened)? Why are you crying? Have you hurt (Did you hurt?...)
9 saw, understood, was working, was writing, didn't notice
10 came, were running and singing, are learning
11 entered, looked, What do you want...) Why did you come (Why have you come?)
12 was raining, left (was leaving), returned, put on, started
13 Has your brother returned...?-Yes, he came...
14 Have you been to...?-When were you there? - I was...
15 Where is...?-He has just come home. He is taking a shower...